Electric metal-working



c. R. ARNOLD. ELEUTRIU METAL WORKING.

Patented Jan. 3, 1893.

INVENTUFi! Oral? B, ov rn/old M /Ww L,

UNrrED STATES PATENT FFiCEt CRAIG R. ARNOLD, OF SHARON HILL,PENNSYLVANIA.

ELEGTRIC METAL-WQRKlNG= SPEGIFICATION forming part of Letters Patent no.489,114, dated January 3, 1893.. Application filed May 17, 1892. SerialNo. 433,316= (No model.)

is primarily designed for use in the welding of metals of any kind.

My inven tion is of greet utility in the weld ing or joining of platesor pieces of lead to-- gcther byte directly applied electric are.

I have hereinafter described my invention as carried out in connectionwith that process of arc welding which consists in making the pieces ofmetal to be joined one pole of the electric circuit and forming the areby touch-- ing the metal with e conductor consisting preferably of:tpieee of eurbon and then re moving it slightly to cause an arc to ployupon the metal which is to be Welded or softened, but it will be at thesome time understood that the invention is not limited to such specialmethod of forming thenrc at the surfaces to be heated, other ways beingknown in the art.

lirieily speaking" my invention may be deliued as consisting in the useof an induced or extrn current in the circuit in which the currentforming the arc flows for the purpose to be hereinafter described, suchinduced or extra current serving at one time to oppose the current fromthe main source employed and soother time tom-assist or llow with cpolarity to assist that current. i prefer {to generate this extraorinduced current throughthe net-ion of u self-inductive or reucl'ivecoil interposed between the generator and the work, but do not limitmyself to such it device thus interposed in the circuit.

n the accompanying drum. in rihnvc illustruted in gencrnldisgruniuniticul fushion one form of apparatus for practicing my invention;

in are welding or metal wtu'hiiisbolh when thc trorl-r. forms one polcotthe tenemtorand. it separate tool or eloctrm'let hc other end when thetwo parts oi the work: l'oriu respectively the opposite poles, it iswell known that if potential enough be applied to establish and maintaina full are, but without the interposition of some sort of resistance, adeed short circuit would be established at the moment of contact whichis made preliminarily to the formation of the are and there would resultblowing of fuses or ot the disturbing and objectionable effects of shortcircuiting the generator. Either of two plans might be adopted forcarrying on the process without producing such objectionable effects thefirst of which would be to use a low potential and a high currentstrength, the second to cut down the high potential by ordinaryresistonce. I hove found byexperiincnting in welding lead, for instance,that when these plans are employed a current of approximately fortysinperes in strength is-required. Under these conditions lead, forinstsnce,will oxidize more or less rapidly and theatre be ac companiedby c series ofoxplosions ofg'reutcr or less magnitude.

In the preferred mnnnerof cnrryin out my invention, I propose todispense with the use of any resistance coil or other devicebpernting'simply as a deed resistance and, to interpose in the circuit aself-inductive" or rcnetive coil such as would be formed; by anyordinary electro-muguet whose coils are iuclnded in the circuit, suchdevice being operated in any circuit of higher or lower potential byproperly proportioniug the inductive resistance coil to the poteutiul.The coil thus in terposed in circuit produces two effects, the first ofwhich reduces the potential nt'tho instant 0t completing or forming thecircuit prcliinii'inrily to the production of the are, therebypreventing any ill cll'ects from u ileud short circuit which would beproduced by the positive cont-net of the tool on thoobjcot. The secondetlect (which follows on the breulttiug' of contact to establish theare), is that obtained by the extra current on breakage oi. circuit andwhich is an induced currontussistingthe niniu'or norinul elcctro-uiotivcforce of the source," This induced ei'irrcut carries with it on electricflame or atmosphere which is less oxidizing in its ellect thun it directcurrent would be,

it possible to obtuiurcsults with live umpcrcs by this methodrepresentingubout livecontact or circuit in the work and then form-' ingthe arc and causing it to cease in any proper manner either bylengthening it beyond the power of the main generator to maintain or byotherwise breaking the circuit and then repeating the operation:

In the drawing the generator is typified at A, as an ordinary shuntwound dynamo, but might be any other source of current. The machineshown is supposed to be adapted to supply or maintain upon the mains orwires 2, 3, an approximately constant potential, say of one hundred andten volts.

.0, indicates the work; D, the tool comprising a suitable insulatinghandle supporting the electrode 4, which may be a stick of carbon, aswell understood in the art, said stick of carbon being connected by aflexible conductor 5, or otherwise, 'with one of the mains 2, while thework 0, is connected with the other main.

E, is an electro magnet the coils of which are in the circuit of thework, as shown, in the branch or circuit connecting the mains or wires2, 3, which are supplied with energy from the dynamo or other source.Either one or more electro-magnets might be'employed andsaid magnets maybe of any desired form best adapted to perinitthe coil to operate asareactive or self-inductive coil whereby the extra or induced currentwill be established at the moment of formation of the circuit and whenthe circuit is broken in forming the arc.

What I claim as my invention is:

1. The herein described improvement in metal working by the electricarc, consisting in setting up an extra or induced current in the circuitof the are, as and for the purpose described.

2. The hereindescribed improvement in electric metal working by theelectric are, consisting in opposing the current of the main source byacounter electro-motive force at the instant of completing the circuitthrough the work, as and for the purpose described.

3.'The herein described improvement in electric metal working by theelectric are, consisting in assisting the electro-motive force of themain source-employed for providing the heating are by an induced'currentgenerated in the circuit thereof in any desired manner, as and for thepurpose described. I

4. The herein described improvement in electric metal working by theelectric are, consisting in generating in the circuit between the sourceand the work an extra current both at the instant of the completion ofcircuit just before the formation of the arc and also accompanying theformation of the are.

5. In an electric metal working apparatus, the combination with thegenerator which supplies the are forming current and the work, of one ormore self-inductive or reactive coils interposed between the generatorand the work, as and for the purpose described.

6. In an electric metal working apparatus, the combination,substantially as described, with mains or wires having an approximatelyconstant maintained potential, of a connection from the latter to theare forming electrode, and a self-inductive reactive coil or coilsinterposed in such connection, as and for the purpose described.

Signed at Chester, in the county of Delaware and State of Pennsylvania,this 16th day of May, A. D. 1892.

CRAIG R. ARNOLD.

Witnesses:

It. \VALTER Zoox, J. LENTZ GARRETT.

